Can you ensure that your smoke detector will sense fire and sound the alarm in the middle of the night?In 80 percent of the cases where emergency pulls out, smoke detectors are missing where the fire occurred. In the year of 2009, 118 people in Sweden died in fires ? most of them would have survived if there had been a functioning smoke detector.Earlier development of smoke detectors has mainly been focusing on components that sense smoke and alert in case of fire. But in most cases the problem has not been whether the smoke detector was working or not as fully assembled, but rather that it was missing.